Method and Unit for Extracting a Component From a Gas Mixture and Method for Transporting a Gas, In Particular Hydrogen or Ammonium

Abstract

The present invention relates to an extraction unit for extracting hydrogen from a gas mixture, including a tube or vessel, including a transit channel for passing a gas mixture in a feed-through direction from a receiving opening to a dispensing opening, which tube or vessel is arranged to be received in-line in a gas transport pipe, at least one membrane-electrode assembly arranged in the tube or vessel with at least one anode, a membrane and a cathode. The assembly is arranged such that an anode surface faces the transit channel and that a cathode surface faces away from the transit channel to a drain separated from the feed-through channel. The anode and the cathode are provided with a connector for an electrical voltage source.

Claims

1. An extractionunit for extracting a component, such as hydrogen or ammonium from a gas mixture, comprising: a tube or vessel, comprising a transit channel for passing a gas mixture in a feed-through direction from a receiving opening to a dispensing opening, which tube or vessel is arranged to be received in-line in a gas transport pipe; at least one membrane-electrode assembly arranged in the tube or vessel with at least one anode, a membrane and a cathode, the assembly being arranged such that an anode surface faces the transit channel and that a cathode surface faces away from the transit channel to a drain separated from the feed-through channel, and wherein the anode and the cathode are provided with electrical connectors.

2. The extraction unit according to claim 1, wherein the electrical connectors are for connection to a power source and wherein the anode surface extends non-rectilinearly between the receiving opening and the discharge opening in order to increase a contact length and thereby a contact surface for passing gas, in particular wherein the anode surface is in a meandering, or wherein in a zigzag saw orientation of the anode surface has been established.

3. The extraction unit according to claim 1 , wherein there is a widening in the cross section of the tube or vessel between the receiving opening and the anode surface.

4. The extraction unit according to claim 1, in which there is a taper in the cross section of the tube or vessel between the anode surface and the discharge opening.

5. The extractionunit according to claim 1, wherein at least one baffle extending with a direction component perpendicular to the feed direction is located in the feed channel.

6. The extraction unit according to claim 1, comprising a compressor for the component, such as hydrogen or ammonium connected to the discharge channel, in particular a solid state compressor.

7. The extraction unit according to claim 1, comprising an electrical voltage source connected to the anode and the cathode.

8. The extraction unit according to claim 1, wherein the cathode comprises a channel structure for a cooling liquid.

9. The extraction unit according to claim 1, wherein the cathode comprises a channel structure for moistening the membrane.

10. A method for extracting hydrogen from a gas mixture, comprising passing the gas mixture through an extraction unit according to claim 1, applying an electric voltage between the anode and cathode by means of an electric voltage source and passing the component, such as hydrogen or ammonium extracted from the gas mixture through the discharge channel.

11. The method according to claim 10, wherein the gas mixture is a mixture comprising helium and hydrogen, derived from mining helium from a natural source.

12. The method according to claim 10, wherein the gas mixture is derived from ammonia, split into nitrogen and hydrogen.

13. The method according to claim 10, wherein the gas mixture is a mixture of H.sub.2, CO.sub.2 and CO, in particular a mixture formed by a steam methane reforming process from fossil raw materials such as natural gas and/or light diesels.

14. A method for transporting a component, such as hydrogen or ammonium, comprising supplying the component to a gas or gas mixture, transporting the gas or gas mixture with the component through a gas transport pipe, passing the gas or gas mixture with the component through an extraction unit and withdrawing the component from the gas or gas mixture .

15. The method according to claim 14, wherein the volume percentage is between 5 and 25%, and in particular between 8 and 15%.

16. The method according to claim 10, wherein the current density across the membrane is below 0.5 A/cm.sup.2 and more particularly below 0.3 A/cm.sup.2.

17. The method according to claim 10, comprising supplying a component, such as oxygen, at the cathode side, for moistening the membrane, or cleaning the catalyst from contaminants and thus increasing the efficiency of the apparatus.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0024] The invention will now be elucidated into more detail with reference to the following figures, wherein:

[0025] FIG. 1 shows a sectional view of an extraction unit according to the invention;

[0026] FIG. 2 shows a schematic view of an extraction unit according to the invention; and

[0027] FIG. 3 shows further configuration details to a first type of use of the extraction unit according to the present invention.

DESCRIPTION OF THE INVENTION

[0028] FIG. 1 shows a sectional view of an extraction unit according to the invention, comprising a tube or vessel, comprising a transit channel 6 for passing a gas mixture in a feed-through direction from a receiving opening 1 to a dispensing opening 8, which tube or vessel is arranged to be received in-line in a gas transport pipe, at least one membrane-electrode assembly 4 arranged in the tube or vessel with at least one anode, a membrane and a cathode, the assembly being arranged such that an anode surface faces the transit channel and that a cathode surface faces away from the transit channel to a drain 5 separated from the feed-through channel, and wherein the anode and the cathode are provided with a connector for an electrical voltage source. The anode surface extends non-rectilinearly between the receiving opening and the discharge opening in order to increase a contact length and thereby a contact surface for passing gas. The anode surface is in a meandering orientation.

[0029] There is a widening 2 in the cross section of the tube or vessel between the receiving opening and the anode surface and there is a taper 7 in the cross section of the tube or vessel between the anode surface and the discharge opening. Furthermore, there is a baffle 3 extending with a direction component perpendicular to the feed direction, located in the feed channel.

[0030] FIG. 2 shows a schematic view of the working principle of an extraction unit according to the present invention. The view shows a transit channel 12 for passing a gas mixture, a membrane-electrode assembly comprising an anode 9, a membrane 10 and a cathode 11 and a drain 14 separated from the feed-through channel, and wherein the anode and the cathode are provided with a connector for an electrical voltage source 15. The hydrogen 13 is extracted from the transit channel 12.

[0031] FIG. 3 shows further configuration details of the configuration in FIG. 2, which corresponds to the first type of use of the extraction unit according to the present invention. In this example, a component, such as hydrogen, is added to a gas or gas mixture, which mixture is transported through a pipe or vessel 16, comprising an anode. The membrane 17 is configured for selectively letting the component, in this example hydrogen, pass when a voltage is applied across the cathode and the anode. The cathode 18 is provided with a channel structure, to which water 19 is provided as a cooling liquid by a pump 20, and from which said cooling liquid is drained again. The component, hydrogen as an example, is extracted from the gas mixture and dried by a dryer 21. The component may in a further processing step be compressed to a higher pressure, for instance for filling a vehicle tank.

[0032] The invention may also be described according to the following Clauses.

[0033] 1. Extraction unit for extracting a component, such as hydrogen or ammonium from a gas mixture, comprising: [0034] a tube or vessel, comprising a transit channel for passing a gas mixture in a feed-through direction from a receiving opening to a dispensing opening, which tube or vessel is arranged to be received in-line in a gas transport pipe; [0035] at least one membrane-electrode assembly arranged in the tube or vessel with at least one anode, a membrane and a cathode, the assembly being arranged such that an anode surface faces the transit channel and that a cathode surface faces away from the transit channel to a drain separated from the feed-through channel, and wherein the anode and the cathode are provided with electrical connectors.

[0036] 2. Extraction unit according to clause 1, wherein the electrical connectors are for connection to a power source and wherein the anode surface extends non-rectilinearly between the receiving opening and the discharge opening in order to increase a contact length and thereby a contact surface for passing gas, in particular wherein the anode surface is in a meandering, or wherein in a zigzag saw orientation of the anode surface has been established.

[0037] 3. Extraction unit according to clause 1 or 2, wherein there is a widening in the cross section of the tube or vessel between the receiving opening and the anode surface.

[0038] 4. Extraction unit according to one of the preceding clauses, in which there is a taper in the cross section of the tube or vessel between the anode surface and the discharge opening.

[0039] 5. Extraction unit according to any one of the preceding clauses, wherein at least one baffle extending with a direction component perpendicular to the feed direction is located in the feed channel.

[0040] 6. Extraction unit according to one of the preceding clauses, comprising a compressor for the component, such as hydrogen or ammonium connected to the discharge channel, in particular a solid state compressor.

[0041] 7. Extraction unit according to one of the preceding clauses, comprising an electrical voltage source connected to the anode and the cathode.

[0042] 8. Extraction unit according to any of the preceding clauses, wherein the cathode comprises a channel structure for a cooling liquid.

[0043] 9. Extraction unit according to any of the preceding clauses, wherein the cathode comprises a channel structure for moistening the membrane.

[0044] 10. Method for extracting hydrogen from a gas mixture, comprising passing the gas mixture through an extraction unit according to any one of the preceding clauses, applying an electric voltage between the anode and cathode by means of an electric voltage source and passing the component, such as hydrogen or ammonium extracted from the gas mixture through the discharge channel.

[0045] 11. Method according to clause 10, wherein the gas mixture is a mixture comprising helium and hydrogen, derived from mining helium from a natural source.

[0046] 12. Method according to clause 10, wherein the gas mixture is derived from ammonia, split into nitrogen and hydrogen.

[0047] 13. Method according to clause 10, wherein the gas mixture is a mixture of H.sub.2, CO.sub.2 and CO, in particular a mixture formed by a steam methane reforming process from fossil raw materials such as natural gas and/or light diesels.

[0048] 14. Method for transporting component, such as hydrogen or ammonium, comprising supplying the component to a gas or gas mixture, transporting the gas or gas mixture with the component through a gas transport pipe, passing the gas or gas mixture with the component through an extraction unit according to any of clauses 1-8 and withdrawing the component from the gas or gas mixture according to the method according to clause 9.

[0049] 15. Method according to clause 14, wherein the volume percentage is between 5 and 25%, and in particular between 8 and 15%.

[0050] 16. Method according to any of clauses 10-15, wherein the current density across the membrane is below 0.5 A/cm.sup.2 and more particularly below 0.3 A/cm.sup.2.

[0051] 17. Method according to any of clauses 10-16, comprising supplying a component, such as oxygen, at the cathode side, for moistening the membrane, or cleaning the catalyst from contaminants and thus increasing the efficiency of the apparatus.